(function ($) {
    "use strict";
    $.fn.jQCloud = function (word_array, options) {
        // 容器元素的引用
        var $this = this;
        // 都已ID命名 避免多个标签之间的碰撞
        var cloud_namespace = $this.attr('id') || Math.floor((Math.random() * 1000000)).toString(36);

        // 默认选项值
        var default_options = {
            width: $this.width(),
            height: $this.height(),
            center: {
                x: ((options && options.width) ? options.width : $this.width()) / 2.0,
                y: ((options && options.height) ? options.height : $this.height()) / 2.0
            },
            delayedMode: word_array.length > 50,
            shape: false, // 默认为椭圆形状
            encodeURI: true,
            removeOverflowing: true
        };

        options = $.extend(default_options, options || {});

        // “jqcloud”类添加到容器简单的CSS样式,设置容器宽度/高度
        $this.addClass("jqcloud").width(options.width).height(options.height);

        // 容器的CSS位置不能为“静态”
        if ($this.css("position") === "static") {
            $this.css("position", "relative");
        }

        var drawWordCloud = function () {
            //Helper函数来测试如果一个元素重叠
            var hitTest = function (elem, other_elems) {
                // 两两重叠检测
                var overlapping = function (a, b) {
                    if (Math.abs(2.0 * a.offsetLeft + a.offsetWidth - 2.0 * b.offsetLeft - b.offsetWidth) < a.offsetWidth + b.offsetWidth) {
                        if (Math.abs(2.0 * a.offsetTop + a.offsetHeight - 2.0 * b.offsetTop - b.offsetHeight) < a.offsetHeight + b.offsetHeight) {
                            return true;
                        }
                    }
                    return false;
                };
                var i = 0;
                // 检查元素重叠一个接一个,停止并返回false一旦发现重叠
                for (i = 0; i < other_elems.length; i++) {
                    if (overlapping(elem, other_elems[i])) {
                        return true;
                    }
                }
                return false;
            };

            // 确保每一个重量之前是一个数字排序
            for (var i = 0; i < word_array.length; i++) {
                word_array[i].weight = parseFloat(word_array[i].weight, 10);
            }

            // 排序word_array从最高的词体重最低的一个
            word_array.sort(function (a, b) {
                if (a.weight < b.weight) {
                    return 1;
                } else if (a.weight > b.weight) {
                    return -1;
                } else {
                    return 0;
                }
            });

            var step = (options.shape === "rectangular") ? 18.0 : 2.0,
                already_placed_words = [],
                aspect_ratio = options.width / options.height;

            // 函数画一词,在螺旋通过移动它,直到找到一个合适的空地方。这将是迭代每个单词。
            var drawOneWord = function (index, word) {
                // 定义跨越的ID属性,将这个词,和相关的jQuery选择器字符串
                var word_id = cloud_namespace + "_word_" + index,
                    word_selector = "#" + word_id,
                    angle = 6.28 * Math.random(),
                    radius = 0.0,

                    // Only used if option.shape == 'rectangular'
                    steps_in_direction = 0.0,
                    quarter_turns = 0.0,

                    weight = 5,
                    custom_class = "",
                    inner_html = "",
                    word_span;


                // 扩展词html选项默认值
                word.html = $.extend(word.html, {
                    id: word_id
                });

                // 如果指定的自定义类,把它们放在一个变量并将它从html attrs,避免由jQCloud覆盖类
                if (word.html && word.html["class"]) {
                    custom_class = word.html["class"];
                    delete word.html["class"];
                }

                // 检查是否min(重量)> max(重量)否则使用默认
                if (word_array[0].weight > word_array[word_array.length - 1].weight) {
                    // 线性映射原体重一个离散的规模从1到10
                    weight = Math.round((word.weight - word_array[word_array.length - 1].weight) /
                        (word_array[0].weight - word_array[word_array.length - 1].weight) * 9.0) + 1;
                }
                word_span = $('<span>').attr(word.html).addClass('w' + weight + " " + custom_class);

                // 如果单词添加链接。url属性设置
                if (word.link) {
                    //如果链接是一个字符串,然后使用它作为href链接
                    if (typeof word.link === "string") {
                        word.link = {
                            href: word.link
                        };
                    }

                    // 扩展链接的html选项默认值
                    if (options.encodeURI) {
                        word.link = $.extend(word.link, {
                            href: encodeURI(word.link.href).replace(/'/g, "%27")
                        });
                    }

                    inner_html = $('<a>').attr(word.link).text(word.text);
                } else {
                    inner_html = word.text;
                }
                word_span.append(inner_html);

                // 将处理程序绑定到单词
                if (!!word.handlers) {
                    for (var prop in word.handlers) {
                        if (word.handlers.hasOwnProperty(prop) && typeof word.handlers[prop] === 'function') {
                            $(word_span).bind(prop, word.handlers[prop]);
                        }
                    }
                }

                $this.append(word_span);

                var width = word_span.width(),
                    height = word_span.height(),
                    left = options.center.x - width / 2.0,
                    top = options.center.y - height / 2.0;

                // 保存样式属性的引用,获得更好的性能
                var word_style = word_span[0].style;
                word_style.position = "absolute";
                word_style.left = left + "px";
                word_style.top = top + "px";

                while (hitTest(word_span[0], already_placed_words)) {
                    // 选择形状是矩形的移动这个词在一个矩形螺旋
                    if (options.shape === "rectangular") {
                        steps_in_direction++;
                        if (steps_in_direction * step > (1 + Math.floor(quarter_turns / 2.0)) * step * ((quarter_turns % 4 % 2) === 0 ? 1 : aspect_ratio)) {
                            steps_in_direction = 0.0;
                            quarter_turns++;
                        }
                        switch (quarter_turns % 4) {
                            case 1:
                                left += step * aspect_ratio + Math.random() * 2.0;
                                break;
                            case 2:
                                top -= step + Math.random() * 2.0;
                                break;
                            case 3:
                                left -= step * aspect_ratio + Math.random() * 2.0;
                                break;
                            case 0:
                                top += step + Math.random() * 2.0;
                                break;
                        }
                    } else { // 默认设置:椭圆螺旋形状
                        radius += step;
                        angle += (index % 2 === 0 ? 1 : -1) * step;

                        left = options.center.x - (width / 2.0) + (radius * Math.cos(angle)) * aspect_ratio;
                        top = options.center.y + radius * Math.sin(angle) - (height / 2.0);
                    }
                    word_style.left = left + "px";
                    word_style.top = top + "px";
                }

                // 不呈现词如果外面将容器的一部分
                if (options.removeOverflowing && (left < 0 || top < 0 || (left + width) > options.width || (top + height) > options.height)) {
                    word_span.remove()
                    return;
                }


                already_placed_words.push(word_span[0]);

                // 如果现有调用回调
                if ($.isFunction(word.afterWordRender)) {
                    word.afterWordRender.call(word_span);
                }
            };

            var drawOneWordDelayed = function (index) {
                index = index || 0;
                if (!$this.is(':visible')) { // 如果不可见，那么不要试图拉
                    setTimeout(function () {
                        drawOneWordDelayed(index);
                    }, 10);
                    return;
                }
                if (index < word_array.length) {
                    drawOneWord(index, word_array[index]);
                    setTimeout(function () {
                        drawOneWordDelayed(index + 1);
                    }, 10);
                } else {
                    if ($.isFunction(options.afterCloudRender)) {
                        options.afterCloudRender.call($this);
                    }
                }
            };

            // 迭代drawOneWord上每一个字。迭代的方式完成取决于绘图模式(delayedMode是真或假的)
            if (options.delayedMode) {
                drawOneWordDelayed();
            } else {
                $.each(word_array, drawOneWord);
                if ($.isFunction(options.afterCloudRender)) {
                    options.afterCloudRender.call($this);
                }
            }
        };

        // 延迟执行,以便在浏览器可以渲染云画推算的强化词前的页面
        setTimeout(function () {
            drawWordCloud();
        }, 10);
        return $this;
    };
})(jQuery);